New phenylpiperazines

ABSTRACT

The invention relates to a novel group of phenylpiperazines having interesting pharmacological properties such as a high affinity for the dopamine D 2  receptor and/or the serotonin reuptake site, and the ability to treat conditions related to disturbances in the dopaminergic and/or the serotonergic systems such as anxiety disorders, depression, Parkinson&#39;s disease, and schizophrenia. 
 
The invention relates to a group of novel phenylpiperazine derivatives of the formula (I):  
                 
wherein: X is a group of formula 1, 2, 3, 4, 5, 6, or 7 as defined in the text, m has the value 2 to 6; n has the value 0-2; 
         R 5  and R 6  are independently H or alkyl (1-3C); or R 5 +R 6  represent a group —(CH 2 )— p  wherein p has the value 3-5, and    R 7  is alkyl (1-3C), alkoxy (1-3C), halogen or cyano; or R 6 +R 7  (R 7  at position 7 of the indole group) represent a group —(CH 2 ) q  wherein q has the value 2-4, and salts thereof.

This is a divisional of application Ser. No. 10/069,256, which was accepted under 35 U.S.C. § 371 on Dec. 12, 2002, and claims priority of International Application PCT/EP00/08190, filed Aug. 22, 2000, which claims the priority of European Patent Application 99202710.2, filed Aug. 23, 1999, and Netherlands Patent Application 1012888, filed Aug. 23, 1999, all of which are incorporated herein by reference.

The invention relates to a group of novel phenylpiperazine derivatives of the formula (I):

wherein:

-   -   X is 1) a group of the formula         wherein     -   S₁ is hydrogen or halogen,     -   S₂ and S₃ are independently hydrogen, alkyl (1-6C), phenyl or         benzyl,     -   S₄ represents two hydrogen atoms or an oxo group,     -   S₅ is H or alkyl (1-4C), and     -   Y is CH₂, O or S or 2) a group of the formula         wherein S₁ has the above meaning and Z is CH₂, O or NH, (2-6C),         alkenyl (2-4C) or alkynyl (2-4C), or 3) a group of the formula         wherein S₁ has the above meaning and Z is C, O or N, or 4) a         group of the formula         wherein S₁ has the above meaning, or 5) a group of the formula         wherein S₁ has the above meaning and A is O or NH, linked to the         piperazine ring with position 5 or 8, or 6) a group of the         formula         wherein S₁ has the above meaning and S₆ and S₇ represent         hydrogen atoms or an oxo group, or 7) a group of the formula         wherein one of the dotted lines can represent a double bond, S₁         has the above meaning, and P, T, and Q are independently         nitrogen or NH

or P and T are independently nitrogen or NH and Q is CH or CH₂

or P and Q are independently nitrogen or NH and is CH, CH₂, C-CH₃ or CH-CH₃

or P is nitrogen or NH, and T and Q are independently CH or CH₂ or P is nitrogen or NH, T is CH or CH₂ and Q is sulphur

-   -   m has the value 2 to 6;     -   n has the value 0-2;     -   R₅ and R₆ are independently H or alkyl (1-3C); or R₅+R₆         represent a group —(CH₂)-_(p) wherein p has the value 3-5, and     -   R₇ is alkyl (1-3C), alkoxy (1-3C), halogen or cyano; or R₆+R₇         (R₇ at position 7 of the indole group) represent a group         —(CH₂)_(q) wherein q has the value 2-4, and salts thereof, which         show high affinity for the dopamine D₂-receptor and are good         serotonin reuptake inhibitors (SRI's).

Preferred compounds of the invention are compounds having formula (I) wherein X represents a group of the formula (1), (2) or (3), wherein the symbols have the meanings given above and the salts thereof. Especially preferred are compounds having formula (I) wherein X is the group with the formula (1) wherein S₁=H, S₂=CH₃, S₃=H, S₄=oxo, S₅=H and Y is oxygen, m is 3, R₅=R₆=hydrogen, n is 0 or 1 and R₇ is 5-fluoro, and the salts thereof.

It has been found that the compounds according to the invention show high affinity for both the dopamine D₂ receptor and the serotonin reuptake site. This combination is useful for the treatment of schizophrenia and other psychotic disorders which enables a more complete treatment of all disease symptoms (e.g. positive symptoms and negative symptoms).

However, some of the compounds having formula (I) show (partial) agonist activity at dopamine receptors making them particularly suitable for the treatment of Parkinson's disease.

The compounds show activity as antagonists at dopamine D₂ receptors as they potentially antagonize apomorphine-induced climbing behaviour in mice. The compounds also show activity as inhibitors of serotonin reuptake, as they potentiate 5-HTP induced behaviour in mice.

The compounds are active in therapeutic models sensitive to clinically relevant antipsychotics (e.g. the conditioned avoidance response; Van der Heyden & Bradford, Behav. Brain Res., 1988, 31:61-67) and antidepressants or anxiolytics (e.g. suppression of stress-induced vocalization; van der Poel et al., Psychopharmacology, 1989, 97: 147-148).

In contrast to clinically relevant dopamine D₂ receptor antagonists the described compounds have a low propensity to induce catalepsy in rodents and as such are likely to induce less extrapyramidal side effects than existing antipsychotic agents.

The inhibitory activity of serotonin reuptake inherent in these compounds may be responsible for the therapeutic effects observed in behavioural models sensitive to either antidepressants or anxiolytics.

The compounds can be used for the treatment of affections or diseases of the central nervous system caused by disturbances in either the dopaminergic or serotonergic systems, for example: aggression, anxiety disorders, autism, vertigo, depression, disturbances of cognition or memory, Parkinson's disease, and in particular schizophrenia and other psychotic disorders.

Pharmacologically acceptable acids with which the compounds of the invention can form suitable acid addition salts are for example hydrochloric acid, sulphuric acid, phosphoric acid, nitric acid, and organic acids such as citric acid, fumaric acid, maleic acid, tartaric acid, acetic acid, benzoic acid, p-toluene sulphonic acid, methanesulphonic acid and naphthalene sulphonic acid.

When the compounds comprise a centre of chirality both the racemic mixture and the individual enantiomers belong to the invention.

The compounds and their acid addition salts can be brought into forms suitable for administration by means of suitable processes using auxiliary substances such as liquid and solid carrier materials.

The compounds having formula (I) can be prepared by reaction of a compound of the formula

under basic conditions with a compound of the formula

in which formulae the symbols have the meanings given above, and L is a so-called leaving group such as a halogen atom or a mesylate group.

The piperazine compounds having formula (II) can be obtained as described in EP 0138280, EP 0189612 and/or EP 0900792, or in an analogous manner.

The preparation of the piperazines having formula (II) can be carried out as indicated in schemes (i)-(iv) below. Some of the routes result in optically pure piperazine derivatives.

The starting compounds having formula (III) can be prepared according to methods known for analogues compounds, as described for example in Organic Process Res. and Dev. 1997 (1), 300-310.

The invention will now be illustrated by means of the following Examples:

EXAMPLE 1 Preparation of Compound a,i (See Scheme i)

Step 1 (scheme i): To a solution of chloronitrocatechol (6.45 g, 34 mmol) in dry DMSO (50 ml) was added powdered NaOH (2.72 g, 68 mmol). After stirring for 30 minutes a solution was added of R-glycerolketal mesylate (8.0 g, 38 mmol) in DMSO (20 ml) and this mixture was heated at 80° C. during 24 hours. After cooling to room temperature the reaction mixture was poured into water (200 ml), acidified with 1 N HCl and extracted with methyl t-butylether. The organic fraction was washed with water and dried on MgSO₄. After removal of the drying agent and the solvent in vacuo, the resulting oil was subjected to flash chromatografy (SiO₂, eluent PE/aceton=3/1). Yield 9.29 g (90%) of the S-ketal.

Step 2 (scheme i): To a solution of the S-ketal (31 g, 102 mmol) in acetic acid (120 ml) was added 35% HBr in acetic acid (80 ml) and this mixture was rotated for 2 hours on a rotavapor in a waterbath of 50° C. The reaction mixture was diluted with ethanol (96%, 250 ml), cooled in a salt/ice mixture and then NaOH (50% in water, 250 ml) was added slowly, keeping the temperature below 15° C. After adding ethanol (250 ml) and water (250 ml) the reaction mixture was stirred at room temperature for 16 hours. Then concentrated HCI (about 300 ml) and water were added and the mixture extracted with ethyl acetate. After washing the organic fraction with 5% NaHCO₃ (4×500 ml), the solvent was removed in vacuo and the resulting oil was subjected to flash chromatografy (SiO₂, eluent PE/aceton=3/1). Yield 20.5 g (81 %) of the R-benzodioxane as a yellow oil.

Step 3 (scheme i): To a solution of R-benzodioxane (20 g, 81 mmol) in DMF (200 ml) was added KOH (4.56 g, 81 mmol). After cooling the red solution in ice/aceton dimethyl sulfate (23 ml) was added and the reaction mixture was stirred for 1.5 hours at room temperature. Then more KOH (4.56 g, cooling) was added and the mixture was stirred at room temperature for 16 hours. After adding water (700 ml), the product was extracted with ethyl acetate. The ethyl acetate was removed in vacuo and the resulting oil was subjected to flash chromatografy (SiO₂, eluent PE/aceton=4/1) yielding R-methoxymethylbenzodioxane (12.3 g, 58%) as a yellow oil. [α]_(D) ²⁵=−97° (methanol).

Step 4 (scheme i): To a solution of R-methoxymethylbenzodioxane (5 g, 19 mmol) in ethanol (100 ml) and ethyl acetate (50 ml) was added a catalytic amount of 10% Pd/C and the solution was shaken under atmospheric H₂ pressure at room temperature. After the calculated amount of H₂ was taken up by the reaction mixture, the catalyst was removed by filtration and the filtrate was concentrated in vacuo. Yield 3.7 g (100%) of the corresponding anilino-compound.

Step 5 (scheme i): The anilino-compound (4 g, 2 mmol) and BCEA, i.e. HN(CH₂CH₂CI)₂.HCl (3.7 g, 2 mmol) were dissolved in chlorobenzene (100 ml). The mixture was heated to 150° C. for 16 hours, concentrated in vacuo and purified by flash chromatografy (SiO₂, dichloromethane/methanol/ammonium hydroxide=92/7.5/0.5). Yield 3.67 g (68%) of the piperazine a,i.

EXAMPLE 2 Preparation of Compound No. 126

The route is described above, i.e. reaction of compound (II) with compound (III). The mesylates of formula (III) were prepared from the corresponding alcohols by standard procedures, e.g. with MsCI/Et₃N.

A mixture of the piperazine a,i (3,6 g, 13,6 mmol), the 5-fluoro indole-mesylate (4,1 g, 15,1 mmol), triethylamine (2 ml) and a catalytic amount of KI in CH₃CN (100 ml) was heated under reflux during 18 hours after which the reaction mixture was concentrated in vacuo and purified by chromatografy (SiO₂, dichloromethane/methanol/ammonium hydroxide=92/7.5/0.5). Yield 3,77 of the free base (oil). The free base was dissolved in ethanol and 1 equivalent of fumaric acid in ethanol was added. After removal of the solvent compound no. 126 was obtained (4,3 g, 57%). [α]_(D) ²⁵=−2 ° (methanol)

EXAMPLE 3 Preparation of Compound b,ii (See Scheme ii)

Step 1 (scheme ii): A solution of the aminophenol (37.3 g, 198 mmol), S-lactic acid methyl ester (20 ml) and triphenylphosphine (58 g, 220 mmol) in THF (2000 ml) was cooled in ice/salt (temperature <10° C.). Then a solution of azodicarboxic acid ester (DIAD, 43 ml, 218 mmol) in THF (400 ml) was added slowly. After stirring at room temperature for 18 hours the reaction mixture was concentrated in vacuo and ethanol (500 ml) and 36% HCl (125 ml) were added to the residue. The mixture was heated to 100° C. (development of gas). After cooling the compound was isolated by filtration and washed with 96% ethanol (about 100 ml). Yield 42 g (87%).

Step 2 (scheme ii): This step is similar to step 4 described in scheme i.

Step 3 (scheme ii): This step is similar to step 5 described in scheme i, resulting in the formation of the piperazine b,ii.

EXAMPLE 4 Preparation of Compound No. 89

The route is described above, i.e. reaction of compound (II) with compound (III). The reaction is carried out as described in example 2, starting with the piperazine b,ii. Yield 58% of compound no. 89, [α]_(D) ²⁵==24° (methanol).

EXAMPLE 5 Preparation of Compound c,iii (See Scheme iii)

Step 1 (scheme iii): A solution of the benzomorpholinone (10 g, 41 mmol ; see scheme ii, step 1) and powdered KOH (2.3 g, 41 mmol) in DMF (100 ml) was cooled in ice (temperature <10° C.). After adding 1 equivalent of Mel (2.55 ml, 41 mmol) the reaction mixture was stirred at room temperature for about 1.5 hours and then poured into water. The precipitate was filtered off, washed with water and dried. Yield 10 g (95%) of the NCH₃₋-compound, mp. 191-192; [α]_(D) ²⁵=+7.50° (in THF)

Step 2 (scheme iii): This step is similar to step 4 described in scheme i.

Step 3 (scheme iii): This step is similar to step 5 described in scheme i, resulting in the formation of the piperazine c,iii.

EXAMPLE 6 Preparation of Compound No. 121

The route is described above, i.e. reaction of compound (II) with compound (III). The reaction is performed as described in example 2, starting with the piperazine c,iii. Yield 44% of compound no. 121, [α]_(D) ²⁵=−28° (methanol).

EXAMPLE 7 Preparation of Compound d,iv (See Scheme iv)

Step 1 (scheme iv): Pyridine (81 ml, 1 mol) was added to a solution of 2-hydroxy-5-chloroaniline (143.5 g, 1 mol) in dry CH₂Cl₂. The mixture was cooled in ice (temperature <10° C.) and then a solution of 2-bromo-2-methyl-propionylbromide (163 ml, 1 mol) in CH₂Cl₂ (100 ml) was added slowly. The mixture was stirred at room temperature for 18 hours and was poured into CH₂Cl₂ (5000 ml) and water (2000 ml). The organic layer was washed with water, dried and concentrated in vacuo till about 1 litre. The precipitate was filtered off, washed with CH₂Cl₂ and dried. Yield 231 g (79%) of the bromocompound, mp. 172° C.

Step 2 (scheme iv): To a suspension of the bromocompound (60 g, 205 mmol) in water (95 ml) was added slowly under ice cooling concentrated sulfuric acid (7 ml) followed by 70% HNO₃ (16 ml) and stirring was continued for 2 hours at room temperature. After cooling in ice water the precipitate was filtered off, washed with water and purified by chromatografy (SiO₂, methyl t-butylether). Yield 49 g (71%) of the nitrocompound.

Step 3 (scheme iv): To a solution of the nitrocompound (49 g, 145 mmol) in DMF (500ml) was added K₂CO₃. This mixture was heated for one hour at 150° C., then cooled and poured into a mixture water/ethyl acetate. The organic fraction was washed with sodium bicarbonate (5% in water), HCl (2N) and water respectively. The solvent was removed in vacuo and the residue was purified by flash chromatografy (SiO₂, methyl t-butylether/PE =1/1). Yield 23 g (62%).

Step 4 (scheme iv): This step is similar to step 4 described in scheme i.

Step 5 (scheme iv): This step is similar to step 5 described in scheme i, leading to the formation of the piperazine d,iv.

EXAMPLE 8 Preparation of Compound No. 115

The route is described above, i.e. reaction of compound (II) with compound (III). The reaction is performed as described in example 2, starting with the piperazine d,iv. Yield 20% of compound no. 115.

The compounds listed in the following tables have been prepared according to the method of the above examples. Comp. no X m Y R₅ R₆ (R₇)n R Z A S₆ + S₇ P T Q Remarks 26 form 3 3 — H H 7-F — O — — — — — S₁ = H 27 1 3 CH₂ H H 7-F — — — — — — — S₁-S₅ = H 28 3 3 — H H 7-Cl — O — — — — — S₁ = H 29 3 3 — H H 7-CH₃ — O — — — — — S₁ = H 30 2 3 — H H H 2-CH₂OCH₃ — — — — — — S₁ = H 31 7 3 — H H H — — — — N CH₂ CH₂ S₁ = H 32 1 3 CH₂ H H 6-Cl — — — — — — — S₁-S₅ = H 33 3 3 — H H 6-Cl — O — — — — — S₁ = H 34 3 3 — H H 5-CN — O — — — — — S₁ = H 35 1 3 CH₂ H H 5-CN — — — — — — — S₁-S₅ = H 36 1 3 CH₂ H H 4-Cl — — — — — — — S₁-S₅ = H 37 3 3 — H H 4-Cl — O — — — — — S₁ = H 38 1 6 CH₂ H H H — — — — — — — S₁-S₅ = H 39 1 5 CH₂ H H H — — — — — — — S₁-S₅ = H 40 1 3 CH₂ H H H — — — — — — — S₁-S₄ = H S₅ = CH₃ 41 1 3 S H H H — — — — — — — S₄ = oxo, S₁-S₃ = S₅ = H 42 6 3 — H H H — — — oxo — — — S₁ = H 43 1 3 S H H H — — — — — — — S₁-S₅ = H 44 6 3 — H H H — — — H₂ — — — S₁ = H 45 1 4 CH₂ H H H — — — — — — — S₁-S₅ = H 46 1 3 CH₂ H H 6-F — — — — — — S₁-S₅ = H 47 3 3 — H H 6-F — O — — — — — S₁ = H 48 7 3 — H H H — — — — N CH NH S₁ = H 49 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 50 1 3 CH₂ H H H — — — — — — — S₄ = oxo, S₁-S₃ = S₅ = H 51 form 3 3 — H C₂H₅ 5-CN — O — — — — — S₁ = H 52 3 3 — H H H — NH — — — — — S₁ = H 53 7 3 — H H H — — — — N C(CH₃) NH S₁ = H 54 7 3 — H H H — — — — NH N CH S₁ = H 55 7 3 — H H H — — — — N N NH S₁ = H 56 1 3 CH₂ H H 4-F — — — — — — — S₁-S₅ = H 57 3 3 — H H 4-F — O — — — — — S₁ = H 58 1 3 CH₂ H H 7-Br — — — — — — — S₁-S₅ = H 59 3 3 — H H 7-Br — O — — — — — S₁ = H 60 1 3 O H H H — — — — — — — S₄ = oxo, S₁ = 7-Cl, S₂ = S₃ = S₅ = H 61 2 3 — H H 5-F 2-CH₂OCH₃ — — — — — — S₁ = H 62 1 3 CH₂ H H 5,7-F₂ — — — — — — — S₁-S₅ = H 63 3 3 — H H 5,7-F₂ — O — — — — — S₁ = H 64 2 3 — H H 7-F 2-CH₂OCH₃ — — — — — — S₁ = H 65 5 3 — H H H — — NH — — — — S₁ = H; position 5 66 5 3 — H H 5-F — — NH — — — — S₁ = H; position 5 67 5 3 — H H 7-F — — NH — — — — S₁ = H; position 5 68 2 3 — H H H 3-CH₂OCH₃ — — — — — — S₁ = H 69 2 3 — H H H 2-CH₂OCH₃ — — — — — — S₁ = H 70 2 3 — H H 5-F 2-CH₂OCH₃ — — — — — — S₁ = H 71 2 3 — H H 5-F 3-CH₂OCH₃ — — — — — — S₁ = H 72 2 3 — H H 7-F 3-CH₂OCH₃ — — — — — — S₁ = H 73 2 3 — H H 7-F 2-CH₂OCH₃ — — — — — — S₁ = H 74 1 3 S H H 5-F — — — — — — — S₄ = oxo, S₁-S₃ = S₅ = H 75 2 3 — H H H 3-CH₂OC₃H₇ — — — — — — S₁ = H 76 form. 2 3 — H H 5-F 3-CH₂OC₃H₇ — — — — — — S₁ = H 77 2 3 — H H H 3-CH₂OCH₂C═CH — — — — — — S₁ = H 78 2 3 — H H 5-F 3-CH₂OCH₂C═CH — — — — — — S₁ = H 79 2 3 — H H 7-F 3-CH₂OCH₂C═CH — — — — — — S₁ = H 80 2 3 — H H H 3-CH₂OCH₂CH₂OCH₃ — — — — — — S₁ = H 81 2 3 — H H 5-F 3-CH₂OCH₂CH₂OCH₃ — — — — — — S₁ = H 82 2 3 — H H 7-F 3-CH₂OCH₂CH₂OCH₃ — — — — — — S₁ = H 83 1 3 S H H 5-F — — — — — — — S₁-S₅ = H 84 1 3 S H H H — — — — — — — S₂ = CH₃, S₁ = S₃-S₅ = H 85 1 3 S H H H — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 86 7 3 — H H H — — — — N CH S S₁ = H 87 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 88 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 89 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 90 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 91 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 92 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = CH₃, S₁ = S₃ = S₅ = H 93 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = phenyl, S₁ = S₃ = S₅ = H 94 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = phenyl, S₁ = S₃ = S₅ = H 95 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = phenyl, S₁ = S₃ = S₅ = H 96 2 3 — H H H 3-CH₂OCH₂CH═CH₂ — — — — — — S₁ = H 97 2 3 — H H 5-F 3-CH₂OCH₂CH═CH₂ — — — — — — S₁ = H 98 2 3 — H H 7-F 3-CH₂OCH₂CH═CH₂ — — — — — — S₁ = H 99 2 3 — H H H 2-CH₂OCH₂C═CH — — — — — — S₁ = H 100 2 3 — H H 5-F 2-CH₂OCH₂C═CH — — — — — — S₁ = H 101 form. 2 3 — H H 7-F 2-CH₂OCH₂C═CH — — — — — — S₁ = H 102 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = C₃H₇, S₁ = S₃ = S₅ = H 103 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = C₃H₇, S₁ = S₃ = S₅ = H 104 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = C₃H₇, S₁ = S₃ = S₅ = H 105 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 106 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 107 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 108 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = benzyl, S₁ = S₃ = S₅ = H 109 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = benzyl, S₁ = S₃ = S₅ = H 110 1 3 O H H 7-F — — — — — — — S₄ = oxo, S₂ = benzyl, S₁ = S₃ = S₅ = H 111 2 3 — H H H 3-CH₂OCH₂C═CCH₃ — — — — — — S₁ = H 112 2 3 — H H H 2-CH₂OCH₂C═CCH₃ — — — — — — S₁ = H 113 2 3 — H H 5-F 2-CH₂OCH₂C═CCH₃ — — — — — — S₁ = H 114 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = S₃ = CH₃, S₁ = S₅ = H 115 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = S₃ = CH₃, S₁ = S₅ = H 116 2 3 — H H H 3-CH₂OCH₃ — — — — — — S₁ = H 117 2 3 — H H 5-F 3-CH₂OCH₃ — — — — — — S₁ = H 118 2 3 — H H 5-F 3-CH₂OCH₃ — — — — — — S₁ = H 119 2 3 — H H H 3-CH₂OCH₃ — — — — — — S₁ = H 120 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 121 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 122 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 123 1 3 O H H H — — — — — — — S₄ = oxo, S₂ = S₅ = CH₃, S₁ = S₃ = H 124 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₁ = 7-Cl, S₂ = S₃ = S₅ = CH₃ 125 1 3 O H H 5-F — — — — — — — S₄ = oxo, S₁ = H, S₂ = S₃ = S₅ = CH₃ 126 2 3 — H H 5-F 3-CH₂OCH₃ — — — — — — S₁ = H *R₇ is linked to position 7 of the indole group

Comp. [α]_(D) ²⁵ (in no Salt or free base MP(° C.) methanol) 1 fumarate 192-4 — 2 2-HCl 239-41 — 3 free base 203-4 — 4 ″ 170-1 — 5 3.fumarate 98 — 6 free base 175-6 — 7 4/3. fumarate 140-3 — 8 free base 189-90 — 9 fumarate 200-1 — 10 3/2. fumarate 190-1 — 11 ½. fumarate 210-2 (dec.) — 12 free base 165-7 — 13 free base 70-1 — 14 fumarate 208 — 15 free base amorph — 16 2. fumarate amorph — 17 free base amorph — 18 fumarate >225 (dec.) — 19 fumarate >170 (dec.) — 20 free base amorph — 21 ½. fumarate >245 (dec) — 22 ½. fumarate >165 glass) — 23 free base 176-7 — 24 free base amorph — 25 ½. fumarate amorph — 26 ¾. fumarate amorph — 27 ½. fumarate >240 (dec) — 28 ⅘. fumarate amorph — 29 ″ amorph — 30 3/2. fumarate glass — 31 5/4. fumarate 188-190 — 32 ½. fumarate >230 (dec) — 33 fumarate amorph — 34 fumarate 150-2 — 35 ½. fumarate 247-8 (dec) — 36 ½. fumarate >240 (dec) — 37 fumarate amorph — 38 HCl amorph — 39 HCl amorph — 40 HCl 220-4 — 41 HCl >250 (dec) — 42 ½. fumarate 214-7(dec) — 43 ½. fumarate 240-3 — 44 ½. fumarate 220-2(dec) — 45 HCl amorph — 46 fumarate 223-5 — 47 ⅔. fumarate 200-2 — 48 free base glass — 49 free base 196-7 — 50 free base 181-2 — 51 ½. fumarate 138.5-41 — 52 free base 190-5(dec) — 53 free base glass — 54 free base glass — 55 free base glass — 56 ½. fumarate 185-6 — 57 fumarate 210-1(dec) — 58 2. fumarate amorph — 59 free base amorph — 60 ½. fumarate >250 — 61 fumarate glass — 62 ½. fumarate 245-7 — 63 3/2. fumarate 175-8 — 64 fumarate glass — 65 free base 220-4(dec) — 66 free base 234-6(dec) — 67 free base >280 — 68 HCl glass — 69 fumarate glass +28 (free base), R-conf. 70 fumarate glass +28 (free base), R-conf. 71 fumarate glass — 72 fumarate glass — 73 fumarate glass +25 (free base), R-conf. 74 free base 212.5-14.5 — 75 fumarate glass — 76 fumarate glass — 77 fumarate glass — 78 fumarate glass — 79 fumarate glass — 80 fumarate glass — 81 fumarate glass — 82 fumarate glass — 83 fumarate amorph — 84 free base amorph — 85 free base amorph — 86 ½. fumarate 218-20 — 87 free base glass −26 R-conf. 88 free base glass +27 S-conf. 89 free base glass −24 R-conf. 90 free base glass +24 S-conf. 91 free base 184-5 −25 R-conf. 92 free base 181-3 +25 S-conf. 93 free base glass — 94 free base glass — 95 free base glass — 96 free base 70-3 — 97 free base 73-5 — 98 fumarate glass — 99 fumarate glass +39 (free base), R-conf. 100 fumarate glass +36 (free base), R-conf. 101 fumarate glass +37 (free base), R-conf. 102 free base 158-60 — 103 free base 181-2 — 104 free base 174-6 — 105 free base glass — 106 free base glass — 107 free base glass — 108 free base glass — 109 free base 207-10(dec) — 110 free base 197-9(dec) — 111 fumarate glass — 112 fumarate glass +31 (free base), R-conf 113 fumarate glass +31 (free base), R-conf 114 free base 191-4 — 115 free base 190-2 — 116 free base amorph 0 S-conf. 117 fumarate amorph S-conf. 118 free base amorph R-conf. 119 free base amorph 0 R-conf. 120 free base amorph −31 R-conf. 121 free base amorph −28 R-conf. 122 free base amorph +28 S-conf. 123 free base amorph +32 S-conf. 124 free base amorph — 125 free base amorph — 126 fumarate amorph −2 R-conf. 

1.-7. (canceled)
 8. A compound of the formula (I):

wherein: X is 1) a group of the formula

wherein S₁ is chosen from hydrogen and halogen, and R is chosen from H, alkyl (1-4C), alkoxyalkyl (2-6C), alkenyl (2-4C) and alkynyl (2-4C), or 2) a group of the formula

wherein S₁ has the above meaning and Z is chosen from CH₂, O and NH, or 3) a group of the formula

wherein S₁ has the above meaning, or 4) a group of the formula

wherein S₁ has the above meaning and A is chosen from O and NH, linked to the piperazine ring with position 5 or 8, or 5) a group of the formula

wherein S₁ has the above meaning and S₆ and S₇ are independently chosen from hydrogen atoms and oxo groups, or 6) a group of the formula

wherein one of the dotted lines can represent a double bond, S₁ has the above meaning, and  P, T, and Q are independently nitrogen or NH, or P and T are independently chosen from nitrogen and NH and Q is chosen from CH and CH₂, or P and Q are independently chosen from nitrogen and NH and T is chosen from CH, CH₂, C—CH₃ and CH—CH₃, or P is chosen from nitrogen and NH, T is chosen from CH and CH₂, and Q is sulphur; m has the value 2 to 6; n has the value 0-2; R₅ and R₆ are independently H or alkyl (1-3C); or R₅+R6 represent a group —(CH₂)—_(p) wherein p has the value 3-5, and R₇ is alkyl (1-3C), alkoxy (1-3C), halogen or cyano; or R₆+R₇ (R₇ at position 7 of the indole group) represent a group —(CH₂)_(q) wherein q has the value 2-4, an enantiomer thereof, or a salt of any of the foregoing.
 9. A compound as claimed in claim 8, wherein X represents a group of the formula (2) or (3), wherein the symbols have the meanings in claim 8, an enantiomer thereof, or a salt of any of the foregoing.
 10. A method for preparing a compound, an enantiomer thereof, or a salt of any of the foregoing as claimed in claim 8, comprising reacting a compound having formula (II)

under basic conditions with a compound having formula (III)

in which formulae the symbols having the meanings given in claim 8, and L is a leaving group, to yield the compound, the enantiomer thereof, or the salt of any of the foregoing as claimed in claim
 8. 11. A pharmaceutical composition comprising at least one compound as claimed in claim 8, an enantiomer thereof, or a salt of any of the foregoing and at least one auxiliary substance.
 12. A method of preparing a composition as claimed in claim 11, comprising mixing the at least one compound, an enantiomer thereof, or a salt of any of the foregoing with the at least one auxiliary substance.
 13. A method of treating at least one central nervous system disorder in a human or animal patient in need of such treating, comprising administering at least one compound as claimed in claim 8, an enantiomer thereof, a salt of any of the foregoing, or a combination of the foregoing to the patient in an amount effective for the treating, wherein the at least one central nervous system disorder is chosen from anxiety disorders, depression, Parkinson's disease, and schizophrenia.
 14. The method of claim 13, in which the at least one central nervous system disorder is chosen from schizophrenia.
 15. A compound as claimed in claim 8, wherein X represents a group of the formula (2), wherein the symbols have the meanings given in claim 8, an enantiomer thereof, or a salt of any of the foregoing. 